Objective Testing of Vergence Dysfunction for Diagnosis and Vergence Recovery Convalescence Using Dynamic Vergence Testing Platform Including 3D Head Mounted Display System with Integrated Eye Tracking Technology

ABSTRACT

An objective testing of vergence dysfunction comprising the steps of: providing a head mounted goggle based stimulus generating eye tracking unit to the subject; presenting visual stimulus to the subject, wherein the visual stimulus is in the head mounted goggle based system and forms the optical target stimulus for at least one vergence test; obtaining objective physiologic response of the subject from the head mounted goggle unit based upon each of the visual stimulus presented to the subject in each test; and using the objective physiologic responses to diagnose the presence of vergence dysfunction. On objective portable head mounted goggle based stimulus generating eye tracking unit for vergence testing is discloses as is a method of method of vergence recovery convalescence.

RELATED APPLICATIONS

This application is a continuation in part of International PatentApplication Serial Number PCT/US17/018862 filed Feb. 22, 2017 andpublished as publication number WO 2017-147141, which application andpublication are incorporated herein by reference. International PatentApplication Serial Number PCT/US17/018862 claims the benefit of U.S.Patent Application 62/298,304 filed Feb. 22, 2015 entitled “DynamicVergence Testing Platform Including 3D Head Mounted Display System withIntegrated Eye Tracking Technology for Objective Testing of VergenceDysfunction for Diagnosis and Vergence Recovery for Convalescence.”

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to vergence testing, and more specificallyto quantitative, noninvasive, clinical objective testing of vergencedysfunction for diagnosis and vergence recovery for convalescence. Thepresent invention is also directed to noninvasive rapid dynamic vergencetesting platform including 3d head mounted display system withintegrated eye tracking technology and methods of using the same.

2. Background Information

Traumatic Brain Injury (TBI) is the result of a blunt blow, jolt orblast overpressure to the head that disrupts brain function. The subsetof mild TBI, or mTBI, has represented a harder segment of TBI todiagnose. Within this application mTBI is a subset of TBI. The termsmild TBI (mTBI) and concussion are commonly used interchangeably in theart, and have been linked with Post Traumatic Stress Disorder. Theseverity of head injuries range from a brief change in mental status orconsciousness to extended unconsciousness and amnesia. In severe ormultiple concussion cases, personality changes can occur withdevastating results.

The Centers for Disease Control and Prevention previously estimated thatat least 3.17 million Americans currently have a long-term or lifelongneed for help to perform activities of daily living as a result of aTBI. Currently there are few accepted clinical methods to detect mTBI.The Center for Disease Control (athttp://www.cdc.gov/TraumaticBrainInjury/statistics.html) estimates that“About 75% of TBI's that occur each year are concussions or other formsof mild TBI.” For further background consult the Brain InjuryAssociation of America at www.BIAUSA.org. The Brain Injury Associationof America (BIAA) is the country's oldest and largest nationwide braininjury advocacy organization.

Proper treatment of TBI injury requires an accurate diagnosis of thestructures affected. Neurosensory symptoms, including oculomotor andvestibular (dizziness and balance) disorders, are among the most commondisabilities seen after injury. Proper treatment of TBI injury requiresan accurate diagnosis of the structures affected. The mechanisms ofinjury in TBI cause a variety of abnormalities in the peripheralvestibular mechanisms, central vestibular structures, ocular-motortracts, cerebellum, as well as all portions of the brain communicatingwith these structures. Despite their prevalence, these symptoms anddeficits can be difficult to quantify.

Existing screening and diagnostic tools for mTBI in general which areemployed on patients and which are based on the traditional battery ofvestibular, balance and neurological tests often requires the use oflarge stationary systems (neuro-otologic test center, Barany/rotarychair, ENG/VNG, computerized posturography/balance platforms, etc.).These large systems deploy a full battery of ocular motor, motion,artificial motion, balance and combined tests. Utilizing such devicesmay be practical in hospital settings, but are not useful in forwarddeployed military settings, or remote locations, such as first responderemergency medical technicians (EMTs).

Vergence is an oculomotor function, described as disconjugate movementof the eyes to track objects varying in depth over the binocular visualfield, and is commonly affected following mTBI. Convergenceinsufficiency, determined by static measures of vergence function, haslong been known to result from mTBI specifically a receded near point ofconvergence amplitude; a decreased compensatory fusional ranges at near;and abnormal phoria at near or far (horizontal, vertical).

Further background on TBI assessment systems is disclosed in U.S. Pat.No. 8,568,311 developed by Emory University which discloses an immersivecognitive assessment system which suppresses outside video and audioinputs. The '311 patent, which is incorporated herein by reference,discloses a distinct approach to the TBI assessment from that thepresent development but is helpful to further establish the state of theart, including a relatively comprehensive listing of publications in thefield.

Additional background on mTBI assessment systems is disclosed inInternational Patent Publication WO 2015-051272 developed by IndianaUniversity (Nicholas L. Port—Inventor) which confirms the validity ofvergence testing (along with other parameters) for TBI diagnosis but yetdevelops a distinct battery of tests for mTBI diagnosis which include “aself-paced saccade test, a sinusoidal pursuit test, a step ramp pursuittest and ocular following task and a dynamic random dot task”. The '272publication, which is incorporated herein by reference, thus teaches adistinct approach to the TBI assessment from that of the presentdevelopment but is helpful to further establish the state of the art.

Additionally the applicants have developed noninvasive rapid screeningof mild traumatic brain injury using combination of subject's objectiveoculomotor, vestibular and reaction time analytic variables set forth inpublication number 2015-0335278. See also Publication No. 2016-0270711,Publication No. 2014-0327880 and related U.S. Pat. No. 9,039,632;Publication No. 2014-0192326 and related U.S. Pat. No. 9,039,631; andU.S. Publication Number 2010-0094161 and related U.S. Pat. No.8,585,609, each of which patents and publications are incorporatedherein by reference.

It is the object of the present invention to address the deficiencies ofthe prior art to yield noninvasive rapid dynamic vergence testingplatforms.

SUMMARY OF THE INVENTION

The present invention is drawn to the development of a portable virtualreality device that will facilitate the effective and efficientnoninvasive rapid dynamic vergence testing by forming a platformincluding 3d head mounted display system with integrated eye trackingtechnology for quantitative, noninvasive, clinical objective testing ofvergence dysfunction for diagnosis and vergence recovery forconvalescence. Vergence is an oculomotor function comprisingdisconjugate movement of the eyes to track objects varying in depth overthe binocular visual field.

The summary of the present invention is three fold. First, concussedpatients present with a profile of vergence deficits can be measuredobjectively with a non-invasive, portable system or platform of thepresent invention. Further that objective vergence data may be used as atool in mTBI diagnosis and finally that objective vergence testing canbe used to monitor, track and facilitate mTBI recovery.

One aspect of the invention provides invention provides an objectivetesting of vergence dysfunction comprising the steps of: providing ahead mounted goggle based stimulus generating eye tracking unit to thesubject; presenting visual stimulus to the subject, wherein the visualstimulus is in the head mounted goggle based system and forms theoptical target stimulus for at least one vergence test; obtainingobjective physiologic response of the subject from the head mountedgoggle unit based upon each of the visual stimulus presented to thesubject in each test; and using the objective physiologic responses todiagnose the presence of vergence dysfunction.

One aspect of the invention provides an portable objective testingplatform for vergence testing which may be summarized as including alaptop; and a head mounted goggle based stimulus generating eye trackingunit coupled to the laptop, the unit including a VR screen and twocameras for recording eye movement, wherein the VR screen is configuredto present visual stimulus to the subject, wherein the visual stimulusis in the head mounted goggle based system and forms the optical targetstimulus for at least one vergence test, and wherein the cameras areconfigured to obtain objective physiologic responses of the subject fromthe head mounted goggle unit based upon each of the visual stimuluspresented to the subject in each test.

Another aspect of the present invention is the provision of vergencerecovery convalescence using the dynamic vergence testing platformincluding 3d head mounted display system with integrated eye trackingtechnology comprising the steps of: A. providing a head mounted gogglebased stimulus generating eye tracking unit to the subject; B.presenting visual stimulus to the subject, wherein the visual stimulusis in the head mounted goggle based system and forms the optical targetstimulus for at least one vergence test; C. obtaining objectivephysiologic response of the subject from the head mounted goggle unitbased upon each of the visual stimulus presented to the subject in eachtest; and D. Presenting at least select physiologic response to thesubject; and E. Repeating steps B-D.

These and other advantages are described in the brief description of thepreferred embodiments in which like reference numeral represent likeelements throughout.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic view of the dynamic vergence testing platformincluding 3d head mounted display system with integrated eye trackingtechnology for objective testing of vergence dysfunction for diagnosisand vergence recovery for convalescence;

FIG. 2 is a schematic view of the 3d head mounted display system of thevergence testing platform of FIG. 1;

FIG. 3 schematically illustrates the creation of a vergence target inthe head mounted display system of the vergence testing platform of FIG.1;

FIG. 4 schematically illustrates a background used to facilitatevergence testing in the head mounted display of the vergence testingplatform of FIG. 1;

FIG. 5 schematically illustrates vergence testing physiology;

FIG. 6 is a graph of mTBI subject and control subject response to avergence saccade test performed on the head mounted display of thevergence testing platform of FIG. 1;

FIG. 7 is a graph of mTBI subject and control subject average eyeresponse to the vergence saccade test of FIG. 6;

FIG. 8 is a chart of mTBI subject and control subject average eyeresponse times and amplitudes to the vergence saccade test of FIG. 6;

FIG. 9 is a graph of mTBI subject and control subject response to avergence smooth pursuit test performed on the head mounted display ofthe vergence testing platform of FIG. 1;

FIG. 10 is a chart of summary of results of the mTBI subject and controlsubject eye responses to the vergence smooth pursuit test of FIG. 9;

FIG. 11 is a chart summarizing symmetry results for mTBI subjects andcontrol subjects for a series of vergence testing performed on the headmounted display of the vergence testing platform of FIG. 1;

FIGS. 12 and 13 are charts summarizing linear regression analysis as apredictor of mTBI using the results of the vergence testing performed onthe head mounted display of the vergence testing platform of FIG. 1; and

FIG. 14 is a chart of smooth pursuit vergence testing symmetry of fourmTBI subjects over a two week period using the results of the smoothpursuit vergence testing performed on the head mounted display of thevergence testing platform of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

It is noted that, as used in this specification and the appended claims,the singular forms “a,” “an,” and “the” include plural referents unlessexpressly and unequivocally limited to one referent. Within thefollowing description the terms horizontal and vertical are relative tothe conventional position of the subject's eyes/vision, regardless ofthe subject's actual head position, unless otherwise stated. Namely thesubject's eyes and the center of the subject's vision will generally lieupon a horizontal plane (discounting variations in subject eye positionfor defining these reference directions). The vertical direction isperpendicular to the horizontal extending generally in the planeincluding the subject's chin and the top of their head. Regarding to thesubject invention, there is mounting evidence to support the theory thatvergence dysfunction contributes to disability after mTBI. Similarlythere is mounting evidence to support the theory that vergence recoveryis an important aspect in mTBI convalescence.

The platform or system 100 of the present invention may be categorizedas a type of Video-oculography (VOG) system. VOG systems have beendefined by Richard E. Gans, PhD, who is the Founder and ExecutiveDirector of the American Institute of Balance and he served on the boardof the American Academy of Audiology, in the Hearing Journal: May2001-Volume 54-Issue 5-pp 40, 42 “Video-oculography is a method ofrecording eye movement through the use of digital video cameras. This isa significant change from electronystagmography, which uses the cornealretinal potential, which is the eye's battery-like effect. As the eyesmove side to side and up and down, the corneo-retinal potential'spositive and negative discharge is recorded. VOG technology, however,uses infrared cameras to measure the eye's position. Small cameras,mounted in goggles, track the center of the pupil to provide thelocation of the eye.” Specifically the platform is formed on theI-Portal®—PAS (Portable Assessment System, manufactured and supported byNKI Pittsburgh), a portable 3D head mounted display (HMD) system withintegrated eye tracking technology. This technology is unique because ittests oculomotor and vergence function in an entirely virtualenvironment.

Videonystagmograpy (VNG) is often defined as a technology for testinginner ear and central motor functions, a process known as vestibularassessment and is defined as involving the use of infrared cameras totrace eye movements during visual stimulation and positional changes. AVNG unit is typically a diagnostic system for recording, analyzing andreporting (generally) involuntary eye movements, called nystagmus forinvoluntary movements, using video imaging technology. The eye trackingunit 100, as described in greater detail below, may also be defined as aVNG system 100. VNG systems 100 are considered, for the purpose of thisapplication, to be a subset of the broader VOG terminology

FIG. 1 is a schematic view of the dynamic vergence testing platform orsystem 100 including 3d head mounted display system 10 with integratedeye tracking technology for objective testing of vergence dysfunctionfor diagnosis and vergence recovery for convalescence. The system 100includes the head mounted goggle unit 10, user input device 30,headphones 40 for auditory input for instructions or stimulus and/orsubject isolation, coupled to a laptop 50 to yield a highly portablesystem.

The VOG/VNG system 100 is coupled to the subject and configured topresent a plurality of virtual reality based visual stimulus to thesubject, at least one visual stimulus providing a target stimulus for avisual based neurologic vergence testing. The system 100 is designed toobtain objective physiologic response of the subject from the eyetracking unit based upon the neurologic vergence test associated witheach vergence visual stimulus presented to the subject. The system 100is configured to use the objective physiologic responses to theneurologic vergence tests to diagnose the presence of traumatic braininjury.

Virtual environment exposure, also called virtual reality or VR, hasproven highly efficient and effective in vestibular rehabilitation sincethe experience gained during VR exposure is transferable to the realworld. The VR technology in the present invention is used to provide avisual target for performing a variety of vergence neurologic tests onthe subject. Additionally, the VR use in the rehabilitation of TBIaccelerates the compensation of an acute loss of peripheral or centralvestibular function by improving adaptive modifications of thevestibulo-ocular reflex. The portable system 100 has the potential ofbeing used bedside and in the home to increase rehabilitationcompensation speed and degree.

FIG. 2 is a schematic design of head mounted VOG/VNG goggle unit 10 withOLED micro display or VR screen 12, two sets of optics 14, cameras 16for recording eye movement typically at above 100 hz for vergencetesting, micro LEDs 18 for illumination of the eyes, and a hot mirror.Simply, the VR screen 12 provides the visual stimulus and the cameras 16capture eye response for quick analysis. The details of the VR displayscreen 12 are believed to be known to those or ordinary skill in the artand it allows the system 100 to present visual images or targets to theuser that have a perceived or simulated distance for vergence testing.The eye tracking technology described herein, outside of the vergencetesting described herein, is generally known in the art, and the camerabased eye tracking goggle based unit 10 may use the IPORTAL® brandgoggle based eye tracking cameras and software available from theassignee of this invention.

The combination of the eye tracking and the display of simulateddistanced visual targets allow the VOG/VNG system 100 to automaticallyrun a number of preprogrammed neurologic vergence tests and to recordthe physiologic responses thereto. Although generally known in the art,FIG. 3 schematically illustrates the creation of a target 25 forvergence testing in the unit 10 in which the screen 12 is divided into aleft eye vision field 22 and a right eye vision field 23. The actualmovement, for example along path 27, of the target stimuli 25 in the twofields 22 and 23 is presented separately to each eye. The target 25moves horizontally outward (left in the left field, rightward in theright field) simultaneously, or inward (both toward the nasal centerline), with respect to any fixed position in the two fields 22 and 23.This movement creates the perception of virtual depth, and when trackedby the two eyes, creates convergence and divergence eye movements forvergence testing.

FIG. 4 schematically illustrates a background 24 used to facilitatevergence testing in the head mounted display 10 of the vergence testingplatform 100 of the invention, wherein to enhance the subjectiveexperience of depth, and thereby increase the likelihood of subjectsresponding with appropriate convergence and divergence eye movements,stimuli 25 will be presented in the context of background stimuli 24that will themselves appear as 3 dimensional objects that surround orencompass or otherwise orient the target stimulus in a virtual 3dimensional space. For instance, the target 25 can move within a squaretunnel 24 that has virtual depth. The background square tunnel 25 willhave slight differences in the two images in the two fields 22 and 23,with increasing disparity near the center, which better creates theperception of a field that is farther from the viewer in the center thannear the edges. Additionally the present invention contemplates the useof varying the size of the target 25, in order to maintain perspectiveand to simulate the normal reduction in size of distant objects relativeto closer objects.

FIG. 5 schematically illustrates vergence testing physiology. The device10 will present stimuli forming target 25 to each eye 120 (in thisfigure), each controlled independently, to simulate varying depthtargets 25. Targets 25 can be, for instance, single dot targets, images,or any other visual stimulus that may be rendered on the screen 12.Through the varying of the horizontal shift of each eye's targetsindependently, an impression of varying depth is created for the target25 as the subject converges their eyes 120 (see right eye position ortrace 130 and left eye position or trace 140) on the independent targetsand fuses the two images into a perceived single image or target 25.This is generally well known standard practice for creating virtualdepth in a VR environment of the screen 12. The VR stimulus software forperforming the tests of the present invention is integrated intoexisting vestibular/neurological software for protocol setup, testresults analysis, and to create VR stimulus 25.

Disparity Fusion (Vergence Saccade) Testing

One vergence test, the representative results of which are shown in FIG.6, of the present invention will present targets 25 at different virtualdepths in a punctuated fashion (sudden shifts in target positionfollowed by delays where the targets are stationary), which are referredto here as Vergence Step, or vergence saccade or disparity fusion. Thissaccadic vergence stimulus 25 pattern will encourage subjects to makeresponsive convergence/divergence eye movements (schematicallyrepresented in traces 130 and 140) to fuse the stimuli 25 into a singleperceived image or target 25 and then hold that vergence position untilthe next stimulus change. This disparity fusion test can be summarizedas where subjects visualize the stimulus 25 moving towards and away fromthem in a saccadic manner. The following variables were our keymeasures: Left and right eye Decay time (also called response time),Symmetry of left and right eye movement, Amplitude of-Eye movement, and% of saccade. The I-Portal google system from Neurokinetics issufficient for this testing, however for other platforms the samplingrate of the eye images should be 100 hz (or higher) with a resolution of<0.1°. The testing platform 18 was designed to track 18 variablesassociated with specific physiologic responses for this test, with themajor variables being noted, however any desired variable may be trackedif the system 10 contains sufficient information. For examplemeasurements of the maximum left and right eye acceleration will besubject to the restraints of the sampling rate.

For Vergence Step testing, data will be segmented so that each segmentor cycle is the eye response to a target 25 shift. Measures will bederived both for individual segments and for the testing data as awhole. The following are examples of measures that will be generated bythe method or device for Vergence Step testing, both per segment and forthe whole test: The correlation between the movement of the two eyes inresponse to the target shift, where “correlation” could be any new orstandard method of measuring how the two eye signals are alike, orco-vary (examples: Pearson's correlation, Kendall's Tau, Spearman, orany form of cross-correlation, e.g., correlations at differentrespective offsets of the two signals); The presence and amount ofsaccadic movement (which is distinct from vergence movement), The timefor each eye to respond to target change and reach a steady position,The magnitude of the vergence movement of each eye, and The asymmetry,between the two eyes, of any of the previous three measures (saccades,time, magnitude).

FIG. 6 specifically is a graph of an mTBI subject and a control subjectresponse to a vergence saccade test performed on the head mounteddisplay 10 of the vergence testing platform 100 of FIG. 1. Specificallythe mTBI subject was a 20 year old female with the testing performed 2days after she sustained the injury causing her mTBI. The upper graphshows the position of the target or stimulus 25 jumping between twopositions with the trace of the mTBI subject's right eye 130 and lefteye 140 shown. This evidences the abnormal state in which the left andright eyes are moving in parallel with a symmetry, specifically theinward symmetry (comparison of left to right eye movement in response topresentation of the target 25 at the position “closest” to the subject)of the mTBI subject was 0.71 and the outward symmetry (comparison ofleft to right eye movement in response to presentation of the target 25at the position “farthest” to the subject) of the mTBI subject was 0.88.This is also described as conjugate motion. The lower graph shows theposition of the target or stimulus 25 jumping between the same twopositions as the upper graph (as it is the same test) with the trace ofthe control subject's right eye 130 and left eye 140 shown. The controlsubject was a 32 year old male whose response evidences the generallynormal state in which the left and right eyes are moving in oppositionto each other with a symmetry of at or near −1.0, specifically theinward symmetry (comparison of left to right eye movement in response topresentation of the target 25 at the position “closest” to the subject)of the control subject was −0.97 and the outward symmetry (comparison ofleft to right eye movement in response to presentation of the target 25at the position “farthest” to the subject) of the control subject was−0.91. This is also described as disconjugate motion. A normal symmetryresult for this test approaches −1.0 while abnormal symmetry for thistest is typically above 0.

FIG. 11 shows a summary of results from subjects of this saccadicvergence test. In this particular sample there were 58 control subjectsanalyzed, specifically 42 males (72.4%) and 16 females (27.6%), rangingin age from 22-45 with a mean of 30.5 years (SD 6.8 years). Additionallyin this sample there were 17 total concussed subjects analyzed,specifically 13 males (76.5%) and 4 females (23.5%), ranging in age from20-43 with a mean of 29.1 years (SD 8.1 years. All mTBI subjects andcontrols were tested at three sites: University of Miami Miller Schoolof Medicine; Madigan Army Medical Center; and Naval Medical Center SanDiego. All mTBI subjects were diagnosed with mTBI by an emergency roomphysician. mTBI subjects tested using the following time line: 24-48hours post injury; 1 week post injury and 2 weeks post in jury. Allcontrol subjects were tested one time.

FIG. 7 is a graph of an mTBI subject and a control subject average eyeresponse over multiple trials to the vergence saccade test of FIG. 6. Inthis graph the mTBI subject is a 25 year old female with the testundertaken 2 days post injury. The control is a 30 year old female. FIG.8 is a chart of mTBI subject and control subject decay times (a measureof response) and amplitudes to the vergence saccade test of FIG. 6 andthe test subjects shown in FIG. 7. It is readily apparent that thecurves are different between the two subjects in how closely they matchthe graph of NL physiologic response 150. As as seen in the table ofFIG. 8, significantly higher values for decay time and significantlylower values for eye amplitude were seen in both inward and outwardtarget movement for the mTBI subject compared to the control subject

Vergence Smooth Pursuit Testing

Another vergence test of the method or device 100 will present acontinuously, smoothly transitioning movement of the stimuli 25,creating the appearance of a target 25 gradually moving toward or awayfrom the subject in the virtual depth space. This will encouragesubjects to make continually updated, smoothly transitioning convergenceand divergence movements. Here we refer to this as “Vergence Pursuit” orvergence smooth pursuit. For the vergence smooth pursuit test, subjectsvisualized the stimulus 25 moving towards and away in a sinusoidalpattern at 0.1 Hz. The following variables were determined to be keyvariables for analysis, namely Near and far angle (measures of the angleof the left and right eye with the target 25 at the nearest point andthe farthest point, respectively, in its sinusoidal movement), Excursion(a measure of the difference between the near and far angle, or anamplitude measurement), Lag time (a measure of the delay between targetmovement and tracking eye movement) and Symmetry (a measure of thecomparison of the left and the right eye movements).

For Vergence Pursuit testing, data will be both segmented intoindividual cycles (sub-segments of the target movement profile, e.g.,cycles of a sinusoidally-modulated stimulus) and analyzed per cycle, oranalyzed for the whole test. The following are examples of measures thatwill be generated by the method or device for Vergence Pursuit testing,both per cycle and for the whole test: The correlation between themovements of the two eyes during target presentation (where“correlation” or symmetry is as defined for Vergence Step testingabove); The lag (temporal shift) of the eye movement relative to thevirtual position of the stimulus; The amplitude or gain of the eyeposition relative to the virtual position of the stimulus at any or alltime points during the test; The presence and amount of saccadicmovement during the test; and The asymmetry, between the two eyes, ofany of the previous three measures (saccades, lag, gain).

FIG. 9 is a graph of an mTBI subject and a control subject responses toa vergence smooth pursuit test performed on the head mounted display 10of the vergence testing platform 100 of FIG. 1. FIG. 10 is a chart ofsummary of results of the mTBI subject and control subject eye responsesto the vergence smooth pursuit test of FIG. 9. Specifically the mTBIsubject was a 20 year old female with the testing performed 2 days aftershe sustained the injury causing her mTBI, while the control was a 32year old male. A cursory review of the two graphs makes clear that theeye movement (curves) between the two subjects are quite different. Notein the table, the near normal symmetry value of the control subjectapproaching −1.0 (−0.91) compared to the mTBI subject's value greaterthan +0.9. Additionally, small lag values are seen for the controlsubject while significantly larger values are seen in the mTBI subject.

FIG. 11 is a chart summarizing symmetry results for mTBI subjects andcontrol subjects for a series of vergence testing performed on the headmounted display of the vergence testing platform of FIG. 1. Analysis ofvariance noted a high degree of vergence symmetry deficits in the mTBIgroup that were not present in the control group with p values less0.001 for both disparity fusion symmetry and vergence smooth pursuitsymmetry.

Logistic regression analysis of this data for both vergence tests shownin FIGS. 12 and 13 demonstrated that abnormalities were virtuallynon-existent in control subjects and present in about half of mTBIsubjects. A 95% confidence interval for symmetry values in controlsubjects fell in the range of −1.0 to −0.87. The presence of anyvergence abnormalities in the testing paradigm was largely diagnostic ofmTBI, in other words abnormal results were essentially only seen in mTBIsubjects. FIGS. 12 and 13 are charts summarizing linear regressionanalysis as a predictor of mTBI using the results of the vergencetesting performed on the head mounted display of the vergence testingplatform of FIG. 1.

FIG. 14 is a chart of smooth pursuit vergence testing symmetry of fourmTBI subjects over a two week period using the results of the smoothpursuit vergence testing performed on the head mounted display of thevergence testing platform of FIG. 1. As shown in FIG. 14, significantimprovement in results compared with control levels was exhibited inthese subjects over a two week period.

Vergence deficiencies can be objectively measured and characterizedusing the portable, 3D head mounted display system 100 with integratedeye tracking technology. Characterizing vergence function in healthycontrols and pathologic dysfunction in mTBI patients as evidenced hereinis an additional tool in the management and study of individuals withmTBI. Vergence data may be used as a tool in the diagnosis of mTBI andreturn to activity decision making.

Objective Measurement of Minimal Vergence Angle (Minimal VergenceDistance)

The vergence testing platform 100 of FIG. 1 using the smooth pursuitvergence testing provides for objective measurement of minimal vergenceangle or minimal vergence distance. The minimal vergence angle orminimal vergence distance is the point where the subject's eyes nolonger resolve a single target such that the subject generally willbegin to see two stimuli. The minimal vergence angle is the angle of theeye at this point and will correspond to a minimal vergence distance infront of the subject. In prior art mechanical vergence systems thesubject may be prompted to indicate when they see two stimuli or targetsas a target is advanced toward the subject in order to attempt tomeasure this physiologic parameter of minimal vergence angle ordistance. In the present platform 100, the subjects eye responsesthroughout the above smooth pursuit vergence testing can be tracked andeye oscillations above a threshold can be used as an indication of thesubject reaching minimal vergence angle. The platform yields anobjective measure for this physiologic parameter.

Offset Vergance Testing

A further variation to the first two tests is the alignment of thetarget 25. In the illustrated example above the target 25 is virtuallyaligned between the two eyes, generally a standard in vergence testing,and the movement is along a horizontal line (Line of Testing). In thepresent invention, either of the first two tests (VERGENCE SMOOTHPURSUIT and VERGENCE SACCADE) may have the alignment of the Line of Testshifted from this center position. Of particular interest is analignment of the Line of Test of the test target 25 with one or theother eye (e.g., a horizontal offsetting of the location of the Line ofTest of the test target 25 from the center location) and performing thevergence smooth pursuit and vergence saccade type vergence testing witha Line of Test aligned with one or the other eye. Such an eye aligningoffsetting of the Line of Test will greatly affect the normal symmetryfor either the vergence smooth pursuit and the vergence saccade typevergence testing, but such placement can increase the magnitude ofresults for one of the eyes, such as the near and far angle of the eyethat is not aligned with the target 25. This can be particularly helpfulin obtaining objective measurements for the objective measurement ofminimal vergence angle for each eye independently of the other.

The performance of the vergence testing with the Line of Testpositioning aligned with one eye can also isolate other issues withresults from the aligned eye. For example if the eye that is alignedwith the target 25 jumps off target 25 with a saccadic movement, then itis not the aligned eye's vergence movement that in error as no eyemovement was necessary for at least that eye in this movement. Thesemodifications of the vergence smooth pursuit and vergence saccade typevergence testing are called offset vergence testing. This type of offsetvergence testing yields improved assessment of subject thresholds andbetter comparisons of left and right eye disparities.

Vertically Adjusted Vergance Testing

The adjustment of the horizontal Line of Test for vergence smoothpursuit and vergence saccade type vergence testing along a horizontalplane forms the offset vergence testing described above and is usefulfor isolating single eye movements as discussed above. The presentinvention further provides for adjustment or movement of the horizontalLine of Test for vergence smooth pursuit and vergence saccade typevergence testing from the conventional center positon along a verticalplane forms a distinct testing known herein as Vertically AdjustedVergence Testing. Performing Vertically Adjusted Vergence Testing, bothabove and below the center of vision, can be used to enhance measureddiscrepancies between left and right eye movements of the subject.Typical vertical adjustment would be expected to be at least 10 degreesabove or below center to yield significant additional physiologicparameters for the subject.

The Vertically Adjusted Vergence Testing can be combined with the offsetvergence testing described above to have the horizontal Line of Test forvergence smooth pursuit and vergence saccade type vergence testingaligned along a vertical plane through a subject's eye but adjustedabove or below the center of vision, however the alignment no longereliminates the eye movement of the aligned eye in such testing due tothe inclusion of the vertical offset of the line of test.

Full 3-Dimensional Vergence Testing

The vergence testing on the platform 100 is not limited to the specificexamples discussed above in which the target 25 movement along the Lineof Test within a vergence test is maintained within a general horizontalline. A further vergence test of the method or device 100 will presenteither of the vergence smooth pursuit and vergence saccade type vergencetesting in combination with additional horizontal and/or verticalmovement that will create the impression of a target 25 that moves bothin depth relative to, and in position within the visual plane (i.e. thiswill create a target 25 that moves virtually in all three dimensions).In short the Line of Test is no longer in a horizontal line extendingONLY toward and away from the subject. The Line of Test may be angled upor down or sideways. Further the Line of Test need not be a straightline but could form a curved trace or even a loop shape.

This form of testing is referred to herein as “Full 3-DimensionalVergence”. As one example instance, a test could be presented in whichthe target moves smoothly along a virtual trajectory through all 3spatial dimensions, tracing a circle, ellipse, spiral, or any othertrajectory that is at any angle to the visual plane, or thatcontinuously changes angle relative to the visual plane.

Objective Testing of Vergence Dysfunction

The above described invention provides an objective testing of vergencedysfunction comprising the steps of: providing a head mounted gogglebased stimulus generating eye tracking unit to the subject; presentingvisual stimulus to the subject, wherein the visual stimulus is in thehead mounted goggle based system and forms the optical target stimulusfor at least one vergence test; obtaining objective physiologic responseof the subject from the head mounted goggle unit based upon each of thevisual stimulus presented to the subject in each test; and using theobjective physiologic responses to diagnose the presence of vergencedysfunction.

A portable objective testing platform for vergence testing 100 may besummarized as including a laptop 50; and a head mounted goggle basedstimulus generating eye tracking unit 10 coupled to the laptop 50, theunit 10 including a VR screen 12 and two cameras 16 for recording eyemovement, wherein the VR screen 12 is configured to present visualstimulus 25 to the subject, wherein the visual stimulus 25 is in thehead mounted goggle based system 10 and forms the optical targetstimulus 25 for at least one vergence test, and wherein the cameras 16are configured to obtain objective physiologic responses of the subjectfrom the head mounted goggle unit 10 based upon each of the visualstimulus 25 presented to the subject in each test.

Vergence Recovery Convalescence

Another aspect of the present invention is the provision of vergencerecovery convalescence using the dynamic vergence testing platform 100including 3d head mounted display system 10 with integrated eye trackingtechnology comprising the steps of: A. providing a head mounted gogglebased stimulus generating eye tracking unit 10 to the subject; B.presenting visual stimulus 25 to the subject, wherein the visualstimulus 25 is in the head mounted goggle based system 10 and forms theoptical target stimulus 25 for at least one vergence test; C. obtainingobjective physiologic response of the subject from the head mountedgoggle unit 10 based upon each of the visual stimulus 25 presented tothe subject in each test; and D. Presenting at least select physiologicresponse to the subject; and E. Repeating steps B-D.

Subjects with vergence dysfunction are greatly aided when the nature ofthe dysfunction is explained and they have an opportunity to “work” onthe identified deficiency in the course of further vergence testing. Theoffset vergence testing protocols described herein may be particularlywell suited for isolating the eyes requiring the work to facilitateconvalescence using the dynamic vergence testing platform 100. Once adeficiency is noted the subject can be given threshold for a givendeficiency in a given test with the testing protocol repeated until thesubject reaches the given threshold for the session (or lack ofimprovement is noted after a given testing time). A new threshold is setfor subsequent sessions. The positive feedback of reaching improvedresults can facilitate subject gains over time.

It is understood, therefore, that this invention is not limited to theparticular embodiments disclosed, but it is intended to covermodifications that are within the spirit and scope of the invention, asdefined by the appended claims and equivalents thereto. The preferredembodiments described above are illustrative of the present inventionand not restrictive hereof. It will be obvious that various changes maybe made to the present invention without departing from the spirit andscope of the present invention. The precise scope of the presentinvention is defined by the appended claims and equivalents thereto.

What is claimed is:
 1. An objective testing of vergence dysfunctioncomprising the steps of: providing a head mounted goggle based stimulusgenerating eye tracking unit to the subject; presenting visual stimulusto the subject, wherein the visual stimulus is in the head mountedgoggle based system and forms the optical target stimulus for at leastone vergence test; obtaining objective physiologic response of thesubject from the head mounted goggle unit based upon each of the visualstimulus presented to the subject in each test; and using the objectivephysiologic responses to diagnose the presence of vergence dysfunction.2. The objective testing of vergence dysfunction according to claim 1wherein the optical target stimulus is presented in the context ofbackground stimuli configured to appear as 3 dimensional objects thatsurround and orientate the target stimulus in virtual 3 dimensionalspace.
 3. The objective testing of vergence dysfunction according toclaim 2 wherein the background stimuli is in the form of a box tunnel.4. The objective testing of vergence dysfunction according to claim 1wherein at least one vergence test comprises a saccade vergence testthat includes presenting targets at different virtual depths in apunctuated fashion whereby sudden shifts in target position arepresented to the subject followed by delays where the targets arestationary.
 5. The objective testing of vergence dysfunction accordingto claim 4 wherein the objective physiologic responses used to diagnosethe presence of vergence dysfunction includes Left and right eyeresponse time to saccade vergence tests.
 6. The objective testing ofvergence dysfunction according to claim 4 wherein the objectivephysiologic responses used to diagnose the presence of vergencedysfunction includes Symmetry of left and right eye movement of saccadevergence tests.
 7. The objective testing of vergence dysfunctionaccording to claim 4 wherein the objective physiologic responses used todiagnose the presence of vergence dysfunction includes at least one ofi) Left and right eye response time to saccade vergence tests, ii)Symmetry of left and right eye movement of saccade vergence tests, iii)Amplitude of-Eye movement of saccade vergence tests, and iv) % ofsaccade of saccade vergence tests.
 8. The objective testing of vergencedysfunction according to claim 1 wherein at least one vergence testcomprises a smooth pursuit vergence test that includes presenting acontinuously, smoothly transitioning movement of the stimuli configuredto create the appearance of a target gradually moving toward or awayfrom the subject in the virtual depth space.
 9. The objective testing ofvergence dysfunction according to claim 8 wherein the smooth pursuitvergence test comprises having subjects visualized the stimulus movingtowards and away in a sinusoidal pattern at about 0.1 Hz.
 10. Theobjective testing of vergence dysfunction according to claim 8 whereinthe objective physiologic responses used to diagnose the presence ofvergence dysfunction includes at least one of i) measures of the angleof the left and right eye with the target at the nearest point and thefarthest points in its sinusoidal movement in the smooth pursuitvergence testing, ii) a measure an amplitude of eye movement in thesmooth pursuit vergence testing, iii) Lag time which is a measure of thedelay between target movement and tracking eye movement in the smoothpursuit vergence testing, and iv) Symmetry which is a measure of thecomparison of the left and the right eye movements in the smooth pursuitvergence testing.
 11. The objective testing of vergence dysfunctionaccording to claim 1 wherein at least one vergence test comprises anoffset vergence test wherein the optical target stimulus is presented ina line offset from the midline between the subject's eyes.
 12. Theobjective testing of vergence dysfunction according to claim 1 whereinat least offset vergence test includes aligning the target with one ofthe subject's eyes.
 13. The objective testing of vergence dysfunctionaccording to claim 1 wherein using the objective physiologic responsesto diagnose the presence of vergence dysfunction is used to diagnosemTBI.
 14. An portable objective testing platform for vergence testingcomprising A laptop; a head mounted goggle based stimulus generating eyetracking unit coupled to the laptop, the unit including a VR screen 12and two cameras for recording eye movement, wherein the VR screen isconfigured to present visual stimulus to the subject, wherein the visualstimulus is in the head mounted goggle based system and forms theoptical target stimulus for at least one vergence test, and wherein thecameras are configured to obtain objective physiologic responses of thesubject from the head mounted goggle unit based upon each of the visualstimulus presented to the subject in each test.
 15. The portableobjective testing platform for vergence testing according to claim 14wherein the optical target stimulus is configured to be presented on thescreen in the context of background stimuli configured to appear as 3dimensional objects that surround and orientate the target stimulus invirtual 3 dimensional space.
 16. The portable objective testing platformfor vergence testing according to claim 14 wherein at least one vergencetest comprises a saccade vergence test that includes presenting targetsat different virtual depths in a punctuated fashion whereby suddenshifts in target position are presented to the subject followed bydelays where the targets are stationary.
 17. The portable objectivetesting platform for vergence testing according to claim 14 wherein atleast one vergence test comprises a smooth pursuit vergence test thatincludes presenting a continuously, smoothly transitioning movement ofthe stimuli configured to create the appearance of a target graduallymoving toward or away from the subject in the virtual depth space.
 18. Amethod of vergence recovery convalescence using dynamic vergence testingplatform including 3d head mounted display system with integrated eyetracking technology comprising the steps of: A. providing a head mountedgoggle based stimulus generating eye tracking unit to the subject; B.presenting visual stimulus to the subject, wherein the visual stimulusis in the head mounted goggle based system and forms the optical targetstimulus for at least one vergence test; C. obtaining objectivephysiologic response of the subject from the head mounted goggle unitbased upon each of the visual stimulus presented to the subject in eachtest; and D. Presenting at least select physiologic response to thesubject; and E. Repeating steps B-D.
 19. The method of vergence recoveryconvalescence using dynamic vergence testing platform according to claim18 wherein at least one vergence test comprises a saccade vergence testthat includes presenting targets at different virtual depths in apunctuated fashion whereby sudden shifts in target position arepresented to the subject followed by delays where the targets arestationary.
 20. The method of vergence recovery convalescence usingdynamic vergence testing platform according to claim 18 wherein at leastone vergence test comprises a smooth pursuit vergence test that includespresenting a continuously, smoothly transitioning movement of thestimuli configured to create the appearance of a target gradually movingtoward or away from the subject in the virtual depth space.